1. Field of the Invention
The present invention relates to a pattern forming method, a substrate processing method and a mold structure replication method which enable a mold structure to be highly accurately and efficiently replicated without reversing a pattern.
2. Description of the Related Art
In a conventional nanoimprinting method, as shown in FIG. 1, a mold structure 3 having a concavo-convex pattern on its surface is pressed against a resin layer 2 formed on a substrate 1, and the concavo-convex pattern of the mold structure 3 is thus transferred into the resin layer 2. Subsequently, the substrate 1 is etched while convex portions formed in the resin layer serve as a mask. A structure (mold structure) 10 obtained has a transferred pattern which is an inversion of the pattern of the mold structure 3. Japanese Patent Application Laid-Open (JP-A) No. 2007-73712, for example, proposes an anodic oxidation patterning method using a conductive mold structure. In this proposal, however, parts of a substrate which are in positions corresponding to concave portions of the mold structure become convex portions of the substrate after etching, and thus an inversion of the pattern of the mold structure is formed in the substrate.
To produce a mold structure (by replication) having a pattern which is not inverted in accordance with such a nanoimprinting method, it is necessary to carry out nanoimprinting twice (original master→negative pattern→positive pattern).
Consequently, there are such problems that the process becomes complex, the incidence of defects becomes high and there is a decrease in accuracy.
As a pattern forming method other than the nanoimprinting method, JP-A No. 2003-236390 proposes a patterning method utilizing oxidation reaction, in which a photocatalytic pattern is used. In this proposal, however, the gap between the photocatalytic pattern and a substrate into which the pattern is to be transferred causes a decrease in resolution, and thus it is difficult to form a minute pattern of nanometer size.
Accordingly, in reality, provision of the following is hoped for: a pattern forming method, a substrate processing method and a mold structure replication method which make it possible to replicate a mold structure highly accurately by one-time imprinting, reduce the incidence of defects and form a minute pattern efficiently; and a mold structure obtained by the mold structure replication method.